The present invention relates to an electrical connector including a terminal. The terminal is formed by bending a metal strip in a thickness direction thereof.
A conventional electrical connector (a connector) is disclosed in Patent Reference. In the conventional electrical connector disclosed in Patent Reference, a terminal of the connector has a shape of an approximate S-shape combining a U-shape portion with an upside-down U-shape portion. The upside-down U-shape portion or a held portion of the terminal is disposed from an upper direction in a circumferential wall of a housing. The U-shape portion of the terminal includes a contact portion for contacting with a mating terminal of a mating connector.    Patent Reference: Japanese Patent Publication No. 2007-035291
In the conventional electrical connector disclosed in Patent Reference, the housing includes a central wall rising from a bottom wall thereof in a region surrounding by the circumferential wall. The central wall includes a terminal holding groove. The U-shape portion of the terminal is situated along an inner surface of the housing, in other words, from an inner surface of the circumferential wall to a surface of the central wall, through the bottom wall. The U-shape portion has elasticity.
In particular, an elastic arm portion is provided in a portion rising along the surface of the central wall. Most part of the elastic arm portion is situated in the terminal holding groove. The elastic arm portion includes a contact portion at a distal end portion thereof. The contact portion protrudes toward the held portion. The contact portion is formed by bending the distal end portion into an angular shape so that an apex portion of the angular shape is situated outside the terminal holding groove.
When the conventional connector is connected to the mating connector from the upper direction, the apex portion of the contact portion is pressed by the mating terminal, thereby the elastic arm portion is displaced elastically in a direction perpendicular to a direction the connectors are connected (a connecting direction). Accordingly, the contact portion contacts with the mating terminal with a certain contact pressure.
The conventional connector disclosed in Patent Reference is soldered to a circuit board so that the bottom wall thereof is placed on the circuit board. Electronic components including the connector are loaded on an electrical device in a state of being mounted on the circuit board. Therefore, it is demanding to lower a height of the electronic component. Accordingly, the connector needs to have a low height in the connecting direction. Therefore, it is important to shorten the elastic arm portion while maintaining the contact pressure at the contact portion, since the terminal governs the height of the connector most effectively.
In the conventional connector disclosed in Patent Reference, the terminal has a certain height, in other words, the elastic arm portion has a certain length from a lower end portion thereof to the contact portion thereof necessary to be displaced elastically by a certain amount in order to maintain the contact pressure at the contact portion. Further, the contact portion is bent into the angular shape so that the apex portion thereof contacts with the mating terminal.
Therefore, a portion situated upper side of the apex portion functions only for guiding the mating connector, without contribution to contacting with the mating connector, the elastic displacement. Moreover, the portion situated upper side of the apex portion extends an entire length of the elastic arm portion.
On the other hand, it becomes difficult to guide the mating terminal successfully when the portion situated upper side of the apex portion is eliminated. When the contact portion lowers a position thereof as maintaining the angular shape thereof, the elastic arm portion shortens the length thereof, resulting in the lower elasticity. The thinner the terminal is made in order to obtain the sufficient elasticity, the weaker the contact pressure becomes.
In view of the problems described above, an object of the present invention is to provide an electrical connector including a terminal enabling a height of the connector to be lowered, by shortening a height of an elastic arm portion thereof while maintaining an adequate length of the elastic displacement arm portion and a contact pressure.
Further objects and advantages of the invention will be apparent from the following description of the invention.